In general, flexible expansion joints used for coupling conduit pipes for conveyance, supply, service and drainage of service water, sewage, industrial water and others are required to have good adaptability to displacements, e.g. compression, expansion, bending, shearing, torsion, etc., pliability, flexibility, vibration-absorbing property, internal and external pressure resistances and durability.
In view of the above required properties of joints, the present invention has as its object to provide flexible expansion joints of novel construction, by which it is possible to obtain satisfactory properties as enumerated above against any displacement phenomena such as expansion, compression, bending, flexing, shearing, torsion and the like and to assure firm bonding between the tubular flexible body portion and the side pipe for a long duration.